Thanks GRD-4-3L,
I didn't make my problem very clear, too busy trying to get the bmwfix link in. So here it is in a bit more detail:
316i touring E36 1997 with climate control.
The air con cools the air fine out of the face/body vents if the centre vent temp is set to 3 blue (maximum coolness) and both sides are set to 16 degrees. If this vent is turned to warm it gets warm or the digital temp setting is increased, this all seems to work normally?!
But if I select the screen or feet buttons the air is always hot whatever the temp setting or even if the aircon button is depressed.
If I select AUTO at 16 degrees hot air comes out of screen and feet vents while cool air comes out of the face/body vents.
Now here is the best part, if I press the screen demist button the blower comes on full, putting lots of warm, damp air on my screen, instant misting in the process.

I am getting it on an analyser on Monday but just hoped someone knew what was going on.
I will post the results if there are any!!! used

OK that does seem to make more sense however that centre vent temp control is baffling to me because I have never seen anything like that before.

If I have to guess, you have no floor/defrost temperature control (hot air all the time when that mode is selected). It could be temperature actuator stuck, temperature control door/valve/vane stuck/broken, or malfunctioning temperature control circuit.

I have no idea how much of the HVAC module is accessible from crawling into the footwell but if you could get access to HVAC module (big plastic housing containing evap core, heater core, doors/vanes/valves for temperature and mode control), the actuators are always on the outside of the case. In many cases, 1 actuator controls several doors/vanes/valves. The doors/vanes/valves are linked together by cams & links, typically beige or white in colour.

If you can get to the actuator, you should be able to unplug it easily and test the signal being fed into it. You can also remove the actuator and try applying 12V power to see if it moves. If you have removed the actuator, you can then try turning the door/vane/valve 'shaft' yourself. The problem can be as simple as seized cam-link mechanism or just lack of lubrication. The cam-link mechanism is typically design so it lightly 'clicks' into the final position for good air seal. So who knows?

I am sorry I can't clearly diagnose the problem for you due to my lack of knowledge on BMW climate controls. After I get my own in September, I may have additional insights.

I think it is more plausible that BMW could have a temp sensor in the footwell. In cold weather, the footwell is the coldest area of the car so there may be a temp sensor at that location.

If this sensor is malfunctioning and 'think' that it is really cold, it will always give you hottest air available. That may also explain why the vent/body mode works fine.

Yeah, I love the warm air misting the windscreen during 'defrost'. That, however, could only happen if the windshield is colder than the hot air. The hot air can hold onto more moisture and it will release the moisture on any cold surface it finds. That cold surface happens to be the windshield.

Forget about what I said about actuators. I recommend focusing on footwell temperature sensor and getting it replaced.

Hi, I followed Dirty-tool's link about removal of the final stage for fan control. My BM is a right hand drive and it is more difficult as the pedals are in the way. Anyway, I got to see the final stage and unplugged the 5 way connector. Removed the stepper motor to gain more access. I can't see the two screws to undo. All I can see are two hole with no screws and a plastic clip. So I thought on the 2001 model may be they done away with the screws (as this module seems to fail so often!!) and had a plastic clip[ to retain the module. I pushed this clip away but I can't lossen the module. I can't see it all round but there is somthing else holding it in place. There is a screw just underneath holding another part, I undid this but this did not help either.

Anyone out there managed to remove the final stage on a right hand 3 series E46 (mine is 2001 model) and could advise on the detail of removing it without breaking anything in the way!

Hi, I also have a climate control problem on my 2001 320CI E46. I just had a diagnostic check at a friends garage. It showed up a few faults

Fault code 1C AUC Sensor

Fault Code 1E AUC Heating

AUC function inactive

Also it mentioned blower resistor faulty and only drawing 8 volts, told it should be atleast 14 volts. The resistor controls the fan speed.

I am told previous technology resitors would be "all or nothing" but now it may still support other functions and may work. Could explain why the problem is worse when the out side temp is higher and more intermittent.

I am going to change the blower resistor and hopefully this will cure the problem.

With the data we had available we could not find the two fault codes 1C & 1E. Does anyone know BMW fault codes or where you can look them up?

AUC is the auto recirc function. There is a sensor under the hood mounted to the fan shroud. Its a rectangular black box. Probelms with this circuit wont affect any other part of the system, only the recirculation flap. You didnt post any details of your problem so thats all I can offer you at this point.

Got my car looked at yesterday, and thought I would post the results in case anyone else gets a similar problem.

Problem
Always hot air out of screen and feet vents when opened. This was whatever the temperature setting and whether the aircon was switched on or off.
The aircon did work out of the face vents and was controllable via the dial between the centre vents. used

When the car was rigged up to the diagnostic computer there was no communication between the computer and the climate control unit. The mechanic deduced that because of this and the fact that when the climate control unit fails it will always fail to hot air (BMW feel this is safer than cold, especially in winter)! that the climate control panel was defective.

The choices were, recon. panel from BMW £207 , or from a breakers £99.

The breaker asked what the fault was before finalising the sale and told me to check the heater valves (£30 its getting cheaper) before replacing the panel. These are situated (RHD) against the passenger side bulkhead and are two small aluminium cylinders with about three heating pipes and one connector attached to them. Sure enough, two of the three wires to the valves were melted and severed by the heat from the valve body.

10 minutes later, after putting some new connections on and extra insulation tape I had aircon that worked.

Just thought this may help somebody, it might be worth checking the wiring even if you don't have a problem, yet!!!

Well Im going to jump on this band wagon now that it seems we have an expert. Anyway, I live in Florida, Hot and humid in the summer. In the summer my AC will stop working intermittently. If it is really super hot that day and I am in stop and go traffic, forget it, usually never works. If I get on the highway, normally, it will work fine. Now recently I went up north to chicago with the car and in the cooler weather the AC works great, Ice cold. BMW told me it was the Temp sensor, it had been ripped off from under the car. Now this was the pointy one, on the left side i think. I replaced it and nothing changed. Now they tell me that the Auxillary fan is not working right and thats what is causing this. Now the other day i happened to see some wires hanging and realized that another sensor on the right side of the car is missing...it was the round half dollar shaped sensor. Now the wires happened to be stripped and twisted together so I just left them because my AC deos work sometimes and I didnt want to make things worse. Any insight on this one will be great. Pretty soon this will be a full time job for GRD. Thanks for all your help, I hope you can recieve as much help as you have given to everybody.

1. In hot weather, A/C operation is almost non-existent
2. In moderate weather, A/C is intermittent
3. In cooler climate, A/C is ice cold
4. On highway, it works fine
5. Some sensor wires are messed up

This one sounds deceptively simple (you would have to investigate). Your condenser fan/fan-control does not seems to be working properly.

Condenser is the large aluminum heat exchanger in front of the radiator. You can see it through front bumper grills. There will be most likely 2 fans (I am guessing since I do not have my car yet) behind the radiator. Depending on atmospheric conditions, it may use one or both fans at the same time. If it only has 1 large fan, no big deal.

You will always find 2 connections on it, an inlet and an outlet, both of them aluminum tubes. One comes from compressor (approx. 1/2") and the other goes to fire wall (approx. 1/2"~3/8"). Follow one of the tubes until you arrive at the compressor. The compressor also should have 2 connections. 1 thick tubing (approx. 3/4" coming from fire wall, and the other going to condenser (approx. 1/2"). Compressor has a black rotating clutch pulley attached to the engine belt.

This is my guess of what is happening. Condenser operates by passing colder outside air (say 90°F in summer) through the condenser fins to cool the hotter refrigerant passing inside the condenser (about 150°F). The job of the condenser is to turn gaseous refrigerant into liquid. For this to happen, you need a lot of airflow through the condenser.

IF, condenser fan is not turning or not turning enough, imagine what would happen:

1. In hot summer, the gaseous refrigerant does not cool into liquid > poor A/C performance.

2. However, in any weather, if you drive steadily at 30mph or higher, you do not need fan. Outside air and car speed is sufficient to cool the refrigerant > A/C works.

3. In colder climate, just the air movement from the engine fan would be sufficient to cool the refrigerant. Colder air through condenser means higher heat transfer = happy condenser.

4. Stop and go traffic > forget about it.

Follow the steps to troubleshoot what is causing the problem:

1. Turn A/C on at park, open the hood, and check to see if the clutch is engaged (rotating)

2. Observe the radiator/condenser fan to see if it is rotating (it should). If it doesn't this is sure indication that the motor and/or controller and/or wireharness and/or fuse is faulty. The fan should be at highest speed when vehicle is parked.

3. Check the fuse first. If it is OK, then turn off the engine

4. Check the resistance of the fan motor > if it is less than 5 ohms, motor is OK. If it is reading very high (MOhm range), than you have open circuit. Replace motor.

5. Turn the fan with your hand to ensure it rotates easily (with engine turned off, of course). If the fan does not want to turn, check to see if anything is preventing easy rotation of the motor. Otherwise, replace the motor.

6. There should be a black box in close proximity to the motor (I am guessing again.) This is condenser/radiator fan speed controller. If this baby is toast, the fan will not turn or malfunction. This black box should be mounted onto the fan shroud assembly. If you remove it, you will see heat sink underneath (in the airflow). It is difficult to test for this unit and it may be a pricey little bugger.

7. This one is tricky to tell. There should be a pressure switch on the aluminum tube line from compressor to condenser. This switch tells the condenser fan to turn on or vary the speed. If this switch is damaged, then no fan operation. This is highly likely as well. Switch replacement is easy. Remove wire connector. Remove switch. Replace switch with NEW o-ring, then torque it down to spec. Reconnect the connector.

I am quite sure it is the fan motor/controller circuit or the pressure switch. Did you check the engine temperature? If this fan is not working, your engine temperature may go up as well because of no air flow.

Well thanks for all the tips and a great explanation. Here is what I have found so far.

Car was sitting all day in the hot sun it was about 95-98 outside. Started the car and turned on the A/C. I heard the compressor kick on and the fan start to gain speed. Hot air from vents. I opened the hood to verify the fan moving. I have only one fan between the engine and the radiator.
The fan is turning and is blowing air, however I cant verify if its full speed or not. I looked at the compressor and it turning, Im not sure what I would see if the clutch was turning or not, but it was making a clicking noise and if I turned off the A/C the clicking stopped, so I assume its working properly.
All My fuses checked good. Now Im not sure how to check resistance, there is a connector to the fan with 3 prongs on it, can i check it there, or would i need to pull the fan and check it right at the motor itself? With the engine off the fan moves very easely.
Now as far the fan speed controller, I found a black box on top of the shroud and it had a small air filter in it and behind the air filter was a screen, looked like some sort of sensor. Im not sure if this is what you were talking about. But I guess theres not much I can do about that anyway

The air stayed hot for about 5 miles of driving, I got on the highway and it started to get cool about 2 minutes of highway driving, but not ice cold. I drove for about 5 more minutes on the highway and the air went from cool to warm a few times. When I got of the high way it started to get colder and about 15 minutes of driving it was ice cold when i got home.

I have no problems with overheating at all , engine stays the same temp all the time.

And the wires that are broken are on the right side (US passenger) in fron under the bumper. There used to be a small round sensor connected to it and it was just connected under the car to the brush guard which was ripped off along time ago.

I have a big feeling it is the fan like BMW said but I would like to be able to be sure before I spend the money on a new one. But then again how can you be sure its not the speed controller thats not the problem.

I really appreciate the time your taking with me. Thanks for all your help.

The clicking noise you hear is most likely the clutch engaging and disengaging. That is good. That means your low pressure switch is working. Your fan is working. Most importantly, your compressor is working.

If it takes 15 minutes for the A/C to fully cool down, it sounds like low refrigerant charge. With a full charge on highway speed, you should get very cold air in about 3 minutes or less. I don't think it is the fan because at highway speeds, fan IS NOT NEEDED.

In cooler climate, A/C does not need full refrigerant charge. A/C does not have to cool the incoming air (because it is already pretty cool to begin with) so it only needs little bit of refrigerant. In hot climate, A/C needs a lot of refrigerant. Your A/C cannot cool enough because it is lacking refrigerant.

Do one more check. Check for low refrigerant charge (check should be low cost or free). It should read very low (about 10~20% of the charge left). Recharge the system with refrigerant.